methylcellulose and Keratitis

Patients who are comatose or semicomatose are at risk of corneal dryness and ulceration.. To compare and evaluate the effectiveness of two treatments used for the prevention of corneal epithelial breakdown in critically ill patients.. A randomized clinical trial was used. The sample consisted of critically ill patients (age, 15-84 years) with a limited or absent blink reflex in a 14-bed general intensive care unit in a large metropolitan teaching hospital. Ninety-six eligible patients were studied; of these, 36 were excluded and data from the remaining 60 patients were analyzed. Patients were randomized to receive methylcellulose lubricating drops every 2 hours (n = 30) or to have their eyes covered with a polyethylene film to create a moisture chamber (n = 30). The patients' corneas were tested daily for epithelial breakdown using fluorescein drops. Patients were studied for a minimum of 48 hours and a maximum of 1 week.. Eight of the 30 patients in the lubricating drop group had positive fluorescein staining, compared with one in the moisture chamber group.. Our results suggest that a moisture chamber is more effective than lubricating drops in preventing corneal epithelial breakdown in critically ill patients with limited or absent blink reflex.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blinking; Chi-Square Distribution; Coma; Cornea; Critical Care; Humans; Humidity; Keratitis; Lubrication; Methylcellulose; Middle Aged; Ophthalmic Solutions; Pharmaceutic Aids; Polyethylenes

Many patients with keratitis sicca complain that the commercially available artificial tears burn when they are instilled and fail to relieve their distressing symptoms. We examined the effects of altering both the pH and osmolarity of hydroxypropyl methylcellulose tear substitute on the tolerance of 15 patients with varying degrees of keratitis sicca. Approximately equal numbers of patients selected the neutral hypotonic tear preparations and the isotonic or near-isotonic alkaline tear substitutes. The isotonic alkaline tear preparation was preferred by the majority of our patients with moderate or severe dry eyes. A commercially available alkaline tear substitute is needed.

Topics: Adult; Aged; Double-Blind Method; Drug Tolerance; Female; Humans; Hydrogen-Ion Concentration; Hypotonic Solutions; Hypromellose Derivatives; Isotonic Solutions; Keratitis; Male; Methylcellulose; Middle Aged; Osmolar Concentration; Random Allocation; Surface-Active Agents; Tears; Wetting Agents

This article reports on comparative in vitro characterization and in vivo evaluation of pre-formed cellulose-based gels, methylcellulose (MC) and carboxymethylcellulose sodium (CMC) and in situ gel-forming Pluronic F127 (PL) for ocular delivery of ciprofloxacin hydrochloride (Cipro) by using a bacterial keratitis model and histological corneal examination. Drug-polymer interactions were studied employing thermal analysis. Further, different concentrations (1-3% w/w or 10-30% w/w) of gels depending on the nature of the polymer used were prepared, characterized for clarity, pH, rheology and in vitro release. Selected gel formulations were evaluated for ocular delivery to Staphylococcus aureus-infected rabbit corneas; and ocular toxicity through histological examination of the cornea. The results demonstrated no Cipro-polymers physicochemical interactions and pseudoplastic flow for all gels used at 35 °C. Both polymer concentrations and drug solubility in the gels are dominantly the rate-determining factors for in vitro drug release. The corneal healing rate for all gel-based formulations was significantly faster (p < 0.05) than that for Cipro solution-treated rabbits. PL-based gel induced significant swelling/edema of the corneal stroma, compared with MC- and CMC-based gels. In conclusion, cellulose-based polymers have superior ocular tolerability/dramatically less irritant; and superior efficacy with more convenient administration compared with PL and Cipro solution, respectively.

Topics: Animals; Anti-Bacterial Agents; Carboxymethylcellulose Sodium; Ciprofloxacin; Cornea; Delayed-Action Preparations; Female; Gels; Keratitis; Male; Methylcellulose; Poloxamer; Rabbits; Rheology; Staphylococcal Infections; Staphylococcus aureus; Viscosity

Topics: Adult; Aged; Cataract Extraction; Cornea; Debridement; Female; Humans; Keratitis; Male; Methylcellulose; Middle Aged; Postoperative Complications; Prednisolone; Silver Nitrate; Sodium Chloride; Sulfacetamide; Time Factors

Topics: Adult; Anti-Bacterial Agents; Female; Humans; Keratitis; Methylcellulose; Ophthalmic Solutions; Trigeminal Neuralgia

Topics: Drug Therapy; Humans; Idoxuridine; Keratitis; Keratitis, Dendritic; Methylcellulose; Ophthalmic Solutions; Pharmaceutical Vehicles

Topics: Animals; Herpes Simplex; Idoxuridine; Keratitis; Keratitis, Dendritic; Lagomorpha; Methylcellulose; Mice; Pharmacology; Rabbits; Research; Toxicology

Topics: Humans; Iodine; Keratitis; Keratoconjunctivitis Sicca; Methylcellulose